Segmented Wheel Nut Torque and Load Management

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Solution Overview

Problem

Existing wheel nuts require different sizes and tools for studs or bolts of varying diameters, limiting their versatility and strength, especially for larger diameters while maintaining a compatible external tool interface for smaller diameters.

Innovation Solution

A wheel nut design featuring a torque receiving section with an external tool interface but no internal threading, combined with a load bearing section having a threaded internal bore, allowing for separate management of torque and load, enabling stronger construction for larger diameters while using the same tool interface as smaller diameter nuts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a wheel nut is designed with internal threading throughout to mate with larger diameter studs or bolts, then the load bearing capacity is improved, but the external tool interface size must increase, making it incompatible with tools designed for smaller diameter nuts

Engineering Contradiction:
Improveload bearing capacityVSAvoidtool interface compatibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The wheel nut is divided into two distinct sections: a torque receiving section with external tool interface but without internal threading, and a load bearing section with threaded internal bore. This segmentation allows each section to be optimized independently - the load bearing section can be designed for high strength with appropriate thread geometry, while the torque receiving section maintains a standardized external interface for tool compatibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The internal threading is extracted from the torque receiving section and placed only in the load bearing section. This allows the external tool interface to remain unchanged for compatibility with existing tools, while the threaded portion is positioned where it can effectively bear the load without interfering with tool application of torque.

Inventive Principle:
Principle #2Taking out (Extraction)

2Strength

If the material thickness of the load bearing section is increased to provide sufficient strength for larger stud/bolt sizes, then the strength is improved, but the overall size and weight of the wheel nut increases

Engineering Contradiction:
Improvestrength for larger stud/bolt sizesVSAvoidwheel nut weight
Core Design Contradiction:
StrengthVSWeight of stationary object

Solution Approach 1:

The wheel nut exhibits local quality by having different material thicknesses in different sections. The load bearing section has increased material thickness (T1 ≥ 0.29D) where strength is critical for supporting larger studs/bolts, while the torque receiving section has reduced or optimized material thickness where full strength is not required, thereby minimizing overall weight while maintaining necessary strength.

Inventive Principle:
Principle #3Local quality

3Reliability

If the axial length of the second portion is increased to decrease strain response, then the durability is improved, but the overall length of the wheel nut increases

Engineering Contradiction:
Improvestrain responseVSAvoidaxial length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The axial length of the second portion is optimized within a specific range (6-11 mm, preferably 8-11 mm) to achieve the desired strain response characteristics. This parameter optimization balances the need for reduced strain response (improved reliability) with the constraint of maintaining a compact overall length, avoiding excessive elongation of the nut.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3513082B1Wheel nut
Publication Date: 2020.04.15 VOLVO TRUCK CORP
  • EP3513082B1 patent drawingFigure 1
  • EP3513082B1 patent drawingFigure 2~3
  • EP3513082B1 patent drawingFigure 4~5

AI summary

The invention relates to a wheel nut (10) for securing a wheel (12) to a threaded stud or bolt (14) of a vehicle (100), wherein the wheel nut comprises: a torque receiving section (16) with an external tool interface (18); and a load bearing section (22) including a threaded internal bore (24) adapted to mate with the threaded stud or bolt (14), a first portion (26) adapted to contact a washer (28), and a second portion (30) axially arranged between the first portion (26) and the torque receiving section (16). The present invention also relates to a vehicle comprising at least one such wheel nut.